Support AGP kotlin variant sources

[CharlieTap]

AGP has two apis for registering generated code:

variant.sources.java?.addGeneratedSourceDirectory

and

variant.sources.kotlin?.addGeneratedSourceDirectory

If we use the latter KSP does not pick up sources generated.

I had a quick look and I think its relates to this line in particular

ksp/gradle-plugin/src/main/kotlin/com/google/devtools/ksp/gradle/AndroidPluginIntegration.kt

Line 79 in ab9274e

val sources = kotlinCompilation.androidVariant.getSourceFolders(SourceKind.JAVA)

[hfmehmed]

This should be fixed by the above PR in the next release. Thanks for the report.